The present invention relates to foldable boom assemblies for machines for spraying, and in particular to an apparatus for permitting positioning of an outer boom section of a foldable boom assembly in at least two positions relative to an inner boom section.
Foldable boom assemblies are used in the agricultural industry for spraying insecticides and herbicides, and are generally attached to farm vehicles.
Many foldable boom assemblies have an outer boom section that "breaks away" and rotates rearward 90.degree. upon impact with a foreign object such as a fence. This prevents damage to the outer boom section as well as the foreign object. The outer boom section desirably can be manually folded 180.degree. to double back on the inner boom section. Then both boom sections can be pivoted to a position alongside the vehicle extending in a direction parallel to the side of the vehicle.
U.S. Pat. No. 4,200,255 (Schmidt et al. patent) shows such a breakaway arrangement where the pivot axis of a hinge between the inner and outer boom sections is inclined such that after the outer boom section has been rotated rearwardly and the foreign object has been passed, the force of gravity automatically moves the outer boom section forward to its original position.
The Schmidt et al. patent represents a major improvement in breakaway foldable boom assemblies but in order to fully fold the outer boom 180.degree. it is necessary for the outer half of the hinge to be raised vertically to allow the outer boom section to be rotated from the 90.degree. rotated position under the breakaway action to the 180.degree. folded position.